1. Field of the Invention
The present invention relate to a liquid crystal display device and more particularly, to a gate in panel (GIP) type liquid crystal display device in which a gate driver is directly mounted on a thin film transistor array substrate.
2. Description of the Related Art
In general, a liquid crystal display (LCD) device is a display device fo0r displaying a desired image by separately supplying data signals according to image information to pixels arranged in a matrix form and adjusting a light transmittance of the pixels.
To this end, the LCD device includes a liquid crystal panel including pixels arranged in a matrix form and a driver for driving the pixels.
The liquid crystal panel includes an array substrate on which a thin film transistor array is formed and a color filter substrate on which color filters are formed. The array substrate and the color filter substrate are attached with a uniform cell gap therebetween, and a liquid crystal layer is formed at the cell gap between the array substrate and the color filter substrate.
Alignment films are formed on the facing surfaces of the array substrate and the color filter substrate, and rubbed to make liquid crystal of the liquid crystal layer arranged in a regular direction.
In addition, the array substrate and the color filter substrate are attached by a seal pattern formed along outer edges of a pixel part, and a polarizer, a phase difference plate, and the like are provided on outer surfaces of the array substrate and the color filter substrate. The plurality of elements is selectively configured to change a proceeding state of light or a refractive index to thus obtain the liquid crystal panel having high luminance and contrast characteristics.
The LCD device configured as described above will now be described in detail.
FIG. 1 is a schematic block diagram of a general LCD device.
As shown in FIG. 1, the general LCD device includes a liquid crystal panel 10 and a driving circuit unit 20 supplying various signals required for implementing an image.
The liquid crystal panel 10 includes a liquid crystal and first and second substrates attached in parallel with the liquid crystal interposed therebetween, and an array element for driving liquid crystal is provided on an inner surface of the first substrate called an array substrate. That is, a plurality of gate lines 16 and a plurality of data lines 17 are arranged in a crossing manner to define pixels in a matrix form on the array substrate, and a thin film transistor (TFT) is provided at each crossing and connected to pixel electrodes formed at each pixel in a one-to-one manner.
Color filter elements such as common electrodes facing the pixel electrodes with the liquid crystal layer interposed therebetween as well as color filters for color implementation are provided on an inner surface of the second substrate called a color filter substrate, and accordingly, the pixel electrodes, the common electrodes as well as the liquid crystal layer form a liquid crystal capacitor.
The driving circuit unit 20 includes a timing controller 25, a gate driver 21, a data driver 22, and other elements such as an interface, a reference voltage generating unit, a power voltage generating unit, and the like.
The interface relays an external driving system such as a personal computer or the like and the timing controller 25, and the timing controller 25 generates a frame control signal supplied to the gate driver and image data and an image control signal transferred to the data driver 22 by using an image and a control signal transferred from the interface.
The gate driver 21 and the data driver 22 are attached to two adjacent edge portions by the medium of a tape carrier package (TCP) and the like such that the gate lines 16 and the data lines 17 can be connected thereto. The gate driver 21 generates a gate signal to sequentially enable the gate lines 16 by frames in response to a frame control signal of the timing controller 25 to control ON/OFF of the TFTs of each gate line 16. The data driver 22 selects reference voltages corresponding to image data in response to the image data and the image control signal inputted from the timing controller 25, and supplies the same to the data lines.17.
When TFTs selected by the gates lines 16 according to the gate signal of the gate driver 21 are turned on, data signals of the data driver 22 are transferred to the pixels via the corresponding TFTs, and accordingly, liquid crystal is driven by an electric field between the pixel electrodes and the common electrodes. In this process, the reference voltage generating unit generates a digital-to-analog converter (DAC) reference voltage of the data driver 22, and the power voltage generating unit supplies operation power with respect to each element of the driving circuit unit 25 and a common voltage transferred to the common electrodes of the liquid crystal panel 10.
The TFTs for the general LCD device may be divided into amorphous silicon TFT and polycrystalline silicon TFT according to types of materials of a semiconductor layer serving as a conductive channel. In case of using dual-amorphous silicon, the gate driver 21 and the data driver 22 are separately fabricated from the liquid crystal panel 10 and connected to the gate lines 16 and the data lines 17 via a tape automated bonding (TAB) method as shown in FIG. 1.
Thus, in the LCD having the amorphous silicon TFT, because the gate driver and the data driver are separately fabricated and attached to the liquid crystal panel through the TAB method, costs and processes are increased.